In the field of microfabrication represented by fabrication of integrated circuit devices, manufacture of integrated circuits with a higher degree of integration is demanded. For this reason, downsizing of a design rule using a lithography technology is quickly advancing. That is to say, development of a lithography process which can perform microfabrication in a stable manner is strongly promoted.
In such development of a lithography process, it has become difficult to obtain an integrated circuit with a higher degree of integration, specifically, it is difficult to obtain a more detailed pattern at a higher accuracy as compared with those obtained by a general process using a KrF excimer laser or an ArF excimer laser, for example. For this reason, in recent years, a lithography process using electron beams in place of a KrF excimer laser or an ArF excimer laser has been proposed.
There have been a number of reports disclosing a resist material used for the lithography process using electron beams (electron beam resist material). Examples of such reports include (1) a methacryl main chain cut type positive-tone resist such as polymethyl methacrylate (PMMA) (for example, refer to Patent Documents 1 and 2), (2) a chemically-amplified positive-tone resist containing a polyhydroxystyrene resin partially protected by an acid-dissociable group (resin for a KrF excimer laser), novolak (resin for an i-lines), and an acid generator (for example, refer to Non-patent Document 1), and (3) a positive-tone and negative-tone resist containing an organic low molecule having thin film forming capabilities (amorphous properties) such as calixarene and fullerene (for example, refer to Patent Documents 3 to 11) or a resist using a polyhydric phenol compound (for example, refer to Patent Documents 12 and 13). In addition, a chemically-amplified radiation-sensitive composition containing 1,3,5-tris[4-(2-t-butoxycarbonyloxy)phenyl]benzene as an organic low molecule having thin film forming capabilities other than calixarene and fullerene has also been disclosed (for example, refer to Non-patent Document 2).    [Patent Document 1] JP-A-2000-147777    [Patent Document 2] JP-A-11-29612    [Patent Document 3] JP-A-11-322656    [Patent Document 4] JP-A-11-72916    [Patent Document 5] JP-A-9-236919    [Patent Document 6] WO 2005/075398    [Patent Document 7] JP-A-7-134413    [Patent Document 8] JP-A-9-211862    [Patent Document 9] JP-A-10-282649    [Patent Document 10] JP-A-11-143074    [Patent Document 11] JP-A-11-258796    [Patent Document 12] JP-A-2006-267996    [Patent Document 13] JP-A-2006-235340    [Non-patent Document 1] Proc. SPIE. Vol. 5376, 757-764 (2004)    [Non-patent Document 2] J. Photo Sci. and Tech. Vol. 12, No. 2, 375-376 (1999)